The purpose of this study is to compare the estimated adrenal suppression between six different inhaled corticosteroids. Patients with mild asthma not requiring corticosteroid therapy will be recruited as part of this multicenter study. Patients will be randomized to receive either placebo or an inhaled steroid at progressively escalating doses although each patient will inhale a placebo on the first overnight study session. At each of four overnight testing sessions following the placebo session, the patients will inhale either a placebo or steroid at progressively increasing doses. On each study session, the subjects will collect urine for cortisol. They will also have hourly blood samples drawn for cortisol throughout the night following a inhalation of the study drug or placebo at 10 PM. Outcome variables will look at adrenal suppression as indicated by the area under the curve of plasma cortisols and the urine cortisol excretion. Dose response relationships will be compared between the different inhaled steroids and equisystemic doses will be determined.